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This _should_ be a rare edge case as the updateBroker func is only called from updateMetadata which does already do an up-front `client.Close()` check under read-lock before then acquiring the write lock. However, there's potentially a small window of opportunity that if client.Close() was called whilst metadata refresh was in-flight and for whatever reason the updateMetadata goroutine gets pre-empted in-between the readlock release and the write lock acquire then the client could have been closed and so `client.brokers` will be nil. I wouldn't have expected this to ever happen, but it was reported by a user in an older Sarama version in #3391 and there's no harm in adding the nilguard just in case. Signed-off-by: Dominic Evans <[email protected]>
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This _should_ be a rare edge case as the updateBroker func is only called from updateMetadata which does already do an up-front `client.Close()` check under read-lock before then acquiring the write lock. However, there's potentially a small window of opportunity that if client.Close() was called whilst metadata refresh was in-flight and for whatever reason the updateMetadata goroutine gets pre-empted in-between the readlock release and the write lock acquire then the client could have been closed and so `client.brokers` will be nil. I wouldn't have expected this to ever happen, but it was reported by a user in an older Sarama version in IBM#3391 and there's no harm in adding the nilguard just in case. Signed-off-by: Dominic Evans <[email protected]> Signed-off-by: DCjanus <[email protected]>
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This should be a rare edge case as the updateBroker func is only called from updateMetadata which does already do an up-front
client.Close()check under read-lock before then acquiring the write lock. However, there's potentially a small window of opportunity that if client.Close() was called whilst metadata refresh was in-flight and for whatever reason the updateMetadata goroutine gets pre-empted in-between the readlock release and the write lock acquire then the client could have been closed and soclient.brokerswill be nil.I wouldn't have expected this to ever happen, but it was reported by a user in an older Sarama version in #3391 and there's no harm in adding the nilguard just in case.